The Emergency Alert System (“EAS” or “EAS system”) is a national public warning system that requires communication service providers, such as TV and radio broadcasters, cable television systems, wireless cable systems, satellite digital audio radio service (SDARS) providers, direct broadcast satellite (DBS) service providers, and wireline video service providers, to offer to the President the communications capability to address the American public during a national emergency. The system also may be used by state and local authorities to deliver important emergency information such as AMBER (missing children) alerts and emergency weather information targeted to a specific area.
The EAS allows communication providers to send and receive emergency information quickly and automatically, even if their facilities are unattended. If one link in the system for spreading emergency alert information is broken, members of the public have multiple alternate sources of warning. EAS equipment also provides a method for automatic interruption of regular programming, and in certain instances, is able to relay emergency messages in languages other than English.
Along with its capability of providing an emergency message to the entire nation simultaneously, the EAS allows authorized state and local authorities to quickly distribute important local emergency information. A state emergency manager can use the EAS to broadcast a warning from communication service providers in a particular state. EAS equipment in that state, including radio, television stations, as well as in cable television systems, can automatically monitor and rebroadcast the emergency information. Additionally, EAS equipment can directly monitor the National Weather Service (“NWS”) for local weather and other emergency alerts, which local broadcast stations, cable systems, and other EAS participants can then rebroadcast, providing an almost immediate relay of local emergency messages to the public.
The most common form of public interaction is likely through the broadcasting of weather warnings, which may be issued by the National Weather Service (NWS), which is provided by the National Oceanic and Atmospheric Administration (“NOAA”). Television program viewers have likely experienced the audible warning tones interrupting a program, followed by an indication that a warning is to be issued, followed by the warning. The warning may pertain to tornadoes, high winds, flooding, etc.
The EAS system is also periodically tested, and this ensures equipment performs as desired. Such testing also can interrupt video programs, but is usually preceded by an announcement that the EAS event is a test, and not an actual emergency. For purposes of this document, reference to an “EAS event” can be either an actually notification of an emergency, or a test of the system, whereas reference to an “EAS Test” refers only to a test of the system. The initiation of an EAS event is associated with an EAS Alert or Notification.
In cable television systems, an EAS Alert typically interrupts any live broadcast program viewed by the viewers. Reference to a “broadcast program” means any network based regularly scheduled program. On a cable system, channels carrying live broadcasts are also interrupted, and the emergency information is then played in place of the broadcasting programming. When an EAS event occurs during a broadcasting program, for either an over-the-air or cable transmission system, the portions of the broadcast program that have been interrupted are not viewable by the viewer. When the EAS Alert is completed, the broadcast programming resumes in real time. In other words, because resumption occurs at the current point in the broadcast of the program, the information interrupted by the EAS is “lost.”
For cable subscribers that view a broadcast program with a set top box, the occurrence of the EAS information is transparent to the set top box. In other words, the contents of the channel conveying the broadcast channel have been substituted by the emergency information in the cable headend. Thus, the set top box remains tuned to the same channel while the content is replaced with the emergency information in the cable headend. Once completed, the programming resumes.
For cable subscribers viewing a video-on demand program, the operation is slightly different. VOD programs are typically streamed to a viewer using a channel selected by the headend. The cable headend informs the set top box (“STB”) which channel to tune to. The coordination between the headend and the set top box for viewing a VOD program result in creating a “VOD Session.” Typically, when a viewer selects a VOD movie to watch, they are not aware of the procedures required to establish a VOD Session, and typically are not aware that the set top box has tuned to another channel to receive the program.
If an EAS event occurs during a VOD Session, an EAS Alert will result in the cable headend instructing the set top box to suspend the VOD Session. This will result in the set top box reverting back to original channel (which may have been a VOD Menu Selection channel). The cable headend will substitute the EAS information for the VOD Menu Selection information, and this information will then be presented to the viewer.
The above procedure works properly to present EAS information to a viewer of a VOD program. In case of an actual test, the viewer would likely stay tuned to receive additional information, or perhaps change channels to a news oriented program to receive additional information. During an actual emergency, the user typically could not establish a VOD session (nor would most users attempt to do so).
However, as noted previously, the system is periodically tested. Thus, many VOD viewers will have a VOD Session interrupted due to an EAS Test, and will then return to viewing the VOD program. This is done by re-initiating the request for the VOD program, which results in resuming the suspended VOD session. As can be expected, many VOD viewers will want to resume viewing their respective VOD programs after an EAS Test, and this can cause a large number of simultaneous requests to the VOD servers in the cable service provider. The large number of requests can create difficulties in the VOD servers, and potentially even cause the VOD servers to crash, or delay responding in resuming the VOD Sessions.
Thus, systems and methods are required video service providers to effectively and efficiently resume VOD programming after an EAS Test.